Java Bindings for OpenGL: Difference between revisions

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Java Binding for the OpenGL API is a JSR API specification for the Java SE platform which allows to use OpenGL ^[1] on the Java Platform.

Programming concepts

Core OpenGL API and GLU library calls are available from Java through a thin wrapper looking very much as the original OpenGL C API ^[2].

All platform specific libraries (available from the CGL API for Mac OS X, GLX for X Window System, and WGL for Microsoft Windows) are also abstracted out to create a platform independent way of selecting Framebuffer attributes and performing platform specific Framebuffer operations^[3].

Example

This examples shows how to draw a Polygon (without initialization or repaint code) ^[4]. Here is the reference C implementation :

int DrawGLScene(GLvoid)	{
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glLoadIdentity();
   glTranslatef(-1.5f,0.0f,-6.0f);	// Move Left 1.5 Units
   glBegin(GL_TRIANGLES); //Drawing Using Triangles
   glVertex3f( 0.0f, 1.0f, 0.0f); // Top
   glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
   glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
   glEnd();	
   glTranslatef(3.0f,0.0f,0.0f);
   glBegin(GL_QUADS); // Draw A Quad
   glVertex3f(-1.0f, 1.0f, 0.0f);	// Top Left
   glVertex3f( 1.0f, 1.0f, 0.0f);	// Top Right
   glVertex3f( 1.0f,-1.0f, 0.0f);	// Bottom Right
   glVertex3f(-1.0f,-1.0f, 0.0f);	// Bottom Left
   glEnd();
   glFlush();
   return TRUE;
}

Which translates to the following Java implementation :

public void display(GLAutoDrawable gLDrawable) {
  final GL gl = gLDrawable.getGL();
  gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
  gl.glLoadIdentity();
  gl.glTranslatef(-1.5f, 0.0f, -6.0f);
  gl.glBegin(GL.GL_TRIANGLES); // Drawing Using Triangles
  gl.glVertex3f(0.0f, 1.0f, 0.0f); // Top
  gl.glVertex3f(-1.0f, -1.0f, 0.0f); // Bottom Left
  gl.glVertex3f(1.0f, -1.0f, 0.0f); // Bottom Right
  gl.glEnd();
  gl.glTranslatef(3.0f, 0.0f, 0.0f);
  gl.glBegin(GL.GL_QUADS);        // Draw A Quad
  gl.glVertex3f(-1.0f, 1.0f, 0.0f); // Top Left
  gl.glVertex3f(1.0f, 1.0f, 0.0f); // Top Right
  gl.glVertex3f(1.0f, -1.0f, 0.0f); // Bottom Right
  gl.glVertex3f(-1.0f, -1.0f, 0.0f); // Bottom Left
  gl.glEnd();
  gl.glFlush();
}

Implementations

Java OpenGL : The reference implementation, available on Microsoft Windows, Linux, Mac OS X, and Solaris platforms.

References

^ All functions in core OpenGL 2.0 have been included.
^ Except GLU NURBS routines which are not exposed through the public API.
^ Platform-specific extensions are not included in the public API. Each implementation can choose to export some of these APIs via the GL.getPlatformGLExtensions() and GL.getExtension(String) method calls which return Objects whose data types are specific to the given implementation.
^ Borrowed from Nehe tutorial, which code are free to use elsewhere

External links

[1] All functions in core OpenGL 2.0 have been included.

[2] Except GLU NURBS routines which are not exposed through the public API.

[3] Platform-specific extensions are not included in the public API. Each implementation can choose to export some of these APIs via the GL.getPlatformGLExtensions() and GL.getExtension(String) method calls which return Objects whose data types are specific to the given implementation.

[4] Borrowed from Nehe tutorial, which code are free to use elsewhere

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[2]

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[4]